So, I am currently working on a project where we have to make management recommendations for the sites that we encounter. This can be rather tricky, as we have to balance the preservation of important historic and prehistoric sites with the necessity of completing an important energy project (in this case, getting renewable energy facilities on line). It's a hell of a lot better than last year's work in the oil fields, and the intellectual challenge can even be fun, but it's a tricky job nonetheless.
It also, however, once again highlights one of the tensions inherent in being an archaeologist in a resource management setting rather than a research setting. I have described the ways in which we have to evaluate archaeological sites in the past. The issue is that pretty much any and all sites are of potential interest to researchers (my MA advisor even wrote an article for The Journal of California and Great Basin Anthropology arguing that we need to not write off "small" or "limited" sites) because there is no limit to the research questions that academic archaeologists may develop, and therefore no limit to the types of data (or types of site from which they derive that data) that they might need.
By contrast, those of us in the management/compliance side of things have to make our arguments for site preservation based on the criteria of the appropriate federal or state regulations. These regulations are written to balance research interests (which usually wants site preservation) with economic interests (which often requires construction), and therefore, not every site can be protected. The appropriate laws do provide decent criteria to make these calls, which is nice as it gives us ground on which to stand when protecting sites, but there is no way that these criteria can cover every potentially interesting site.
Also, we on the compliance side have to choose our battles. As is, there are plenty of legislators and individuals and organizations that can afford to contribute large amounts of money to legislators who want the National Historic Preservation Act and similar laws repealed. If we fight on every site, and make construction and land development more difficult than it needs to be, we run the risk of tilting public opinion (which is currently in our favor) against us, and emboldening those sorts of attempts. But, of course, if we fold routinely, we make the laws toothless and irrelevant. It's a difficult line to walk.
So, I always feel uneasy when I tell someone that a site is not significant.